Weird error when setting up Cloudmin Services client

I got the following error when trying to add srv1 as the Cloudmin Services master for the new VM I just created there:

Checking login to services host .. .. check failed : Invalid response format : syntax error at (eval 109) line 3, at EOF

It turns out this is because the user I'm trying to set it up with isn't working (when I switch it to a user that I know works, it logs in correctly). So, error is poor. Needs to explain that the user is invalid.

I also need to figure out why my new user doesn't work. Might be a misconfiguration on my part, as the UI isn't entirely obvious for creating Cloudmin users that can access Cloudmin Services.